Clean up code (#844)

Author: wenjun93

vllm/core/scheduler.py

@@ -379,9 +379,6 @@ def _preempt_by_swap(
         seq_group: SequenceGroup,
         blocks_to_swap_out: Dict[int, int],
     ) -> None:
-        seqs = seq_group.get_seqs(status=SequenceStatus.RUNNING)
-        for seq in seqs:
-            seq.status = SequenceStatus.SWAPPED
         self._swap_out(seq_group, blocks_to_swap_out)
         self.swapped.append(seq_group)